Altogether, 5 emperors, 15 empresses, 136 imperial concubines, 3 princes, and 2 princesses of the Qing Dynasty were buried here.
It's a somewhat eerie place with very few amenities and much of it in unrestored. Each tomb follows a very similar pattern: gate, square with large hall, and behind that the tomb itself. So once you've seen one, you've seen them all.
The most important tombs (including Dowager Empress Cixi) were looted in 1928 when a warlord, Sun Dianying, blew open the heavy marble doors and made off with a stash of treasure, including the huge pearl that reportedly lay in Cixi's mouth. The only difference between this and robbing the Great Pyramids was the use of gunpowder and getaway trucks.